Manhole closure assembly with support ring

ABSTRACT

Manhole closure assembly primarily prevents drainage and storm water from emptying into manhole leading to sewerage system. Closure assembly comprises cover plate sealing off manhole opening. First valve member is secured to cover plate for relieving pressure inside manhole when pressure exceeds predetermined amount, and second valve member is secured to cover plate for relieving vacuum inside manhole when vacuum exceeds predetermined amount. Adapter ring is provided for supporting manhole closure assembly when manhole does not include structure for supporting assembly.

United States Patent [191 Campagna Mar. 26, 1974 1 MANHOLE CLOSURE ASSEMBLY WITH SUPPORT RING [76] Inventor: Benjamin ,1. Campagna, 300 Lark Drive, Arbor Park, Newark, Del. 19711 [22] Filed: Jan. 3, 1972 [21] Appl. No.2 214,995

Related US. Application Data Continuation-impart of Ser. No. 89,30], Nov. 13,

1970, Pat. NO. 3,712,009

[52] US. Cl 52/20, 52/198, 52/302 [51] Int. Cl EOZd 29/14 [58] Field of Search 52/19-21, 124,

[56] References Cited UNITED STATES PATENTS 2,009,132 7/1935 Gehris 94/35 507,636 10/1893 Schneider... 137/493.8

1,630,557 5/1927 Woodrow 94/34 984,860 2/1911 Smith 52/547 X 2,834,374 5/1958 Klinkenberg... 137/543.l3 X

243,256 6/1881 Heylmun 137/543 X 579,864 3/1897 Deake et a1 94/34 2,553,934 5/1951 Olyott 94/34 3,131,718 5/1964 Mingrone 137/543 X 11,276 7/1854 Thompson 576,253 2/1897 Bingham 94/37 2,844,164 7/1958 Robbins 137/541 X 574,992 1/1897 Held 137/541 X FOREIGN PATENTS OR APPLICATIONS 394,687 12/1965 Switzerland 94/34 1,131,384 6/1962 Germany 52/547 336,437 10/1930 Great Britain 94/34 Primary Examiner-Frank L. Abbott Assistant ExaminerLeslie A. Braun Attorney, Agent, or FirmConnolly and Hutz 5 7 ABSTRACT Manhole closure assembly primarily prevents drainage and storm water from emptying into manhole leading to sewerage system. Closure assembly comprises cover plate sealing off manhole opening. First valve member is secured to cover plate for relieving pressure inside manhole when pressure exceeds predetermined amount, and second valve member is secured to cover plate for relieving vacuum inside manhole when vacuum exceeds predetermined amount. Adapter ring is provided for supporting manhole closure assembly when manholedoes not include structure for supporting assembly.

3 Claims, 9 Drawing Figures PATENTEDMARZS 1914 $798,848

- sum 2 or 2 MANHOLE CLOSURE ASSEMBLY WITH SUPPORT RING CROSS REFERENCE TO RELATED APPLICATION The present application is a continuation-in-part of applicants copending US. patent application Ser. No. 89,301, filed Nov. 13, 1970 and now US. Pat. No. 3,712,009.

BACKGROUND OF THE INVENTION The present invention relates to a manhole closure assembly, and more particularly to a closure that prevents drainage and storm water from emptying into a manhole that leads to a sewerage system. I

The primary reason for segregating sanitary or sewerage systems from systems designed to handle storm and drainage water is an obvious one. Specifically, when drainage and storm water empties into a sanitary system the sewerage system plant must necessarily handle and treat the storm water in addition to the sewerage material. Such conditions place an unnecessary burden on the sewerage treatment facility. Standard frames and covers for manholes that lead to sanitary or sewerage systems include heavy cover constructions with passageways therein that enable storm water to empty into the sewerage system. The passageways in the standard cover constructions are provided for the purpose of relieving internal pressure in the sanitary system as well as preventing vacuum build-ups in the system. It is impossible to simply seal off or otherwise eliminate the passageways in these covers since pressure developed within the sanitary system could easily produce a force sufficient to blow the cover away from its seated position at the manhole opening or blast the plugs away from the passageways. Additionally, pressure developed within the sanitary system can easily cause damage to the system if that pressure is not relieved. Moreover, unrelieved vacuum within the system can also cause severe damage.

With an overdesigned sewerage system .and/or an over-capacity sewerage treatment plant; storm water draining into the system does not present any significant problems. On the other hand, with many existing systems capacity is at peak level, and 40 percent of that capacity is the direct result of storm or drainage water.

For the most part, storm water volume draining into sewerage systems is much more acute today than it was many years ago, and the key factor is that today there is significantly less impervious area than there was several years ago. This factor is due to larger street areas that collect more drainage water as well as smaller building lot sizes which cut down on the amount of overall impervious area. Such factors have significantly contributed to the problem of overtaxing presentsanitary systems. By significantly preventing storm and drainage water from emptying into sanitary and sewerage systems, existing systems and treatment facilities can easily handle an additional percent or more sewerage capacity.

SUMMARY OF THE INVENTION The primary object of the present invention is to provide a manhole closure assembly that effectively and easily seals off a manhole opening in an efficient and highly economical manner to thereby prevent drainage and storm water from emptying into the manhole while relieving pressure and vacuum build-ups that may occur within the manhole.

In accordance with the present invention a manhole closure assembly is provided for primarily preventing drainage and storm water from emptying into a manhole opening covered by the closure assembly. The closure assembly comprises a cover plate that seals off the manhole opening with a first valve member secured to the plate arranged to relieve pressure inside the manhole when it exceeds a predetermined amount. Additionally, a second valve member also secured to the plate is arranged to relieve vacuum inside the manhole when it exceeds a predetermined amount.

More specifically, the cover plate comprises a pair of semicircular segments and a connector strip that seals and connects the semicircular segments together along their diametral edges. The connector strip has an S- shaped cross section the openings of which are constructed and arranged to snugly receive the diametral portions of the semicircular segments of the cover plate. One valve member is secured to one of the semicircular segments of the cover while the other valve member is secured to the second semicircular segment of the plate. I

In the embodiment of the invention illustrated in the drawing, the manhole closure assembly cooperates with an adapter ring that supports the closure assembly at the manhole opening. The adapter ring comprises a pair of arcuate segments and fastening structure at the ends of the segments for joining them together to form the ring. Preferably, each fastening structure includes an externally threaded rod and internally threaded constructions associated with the ends of the ring segments for receiving the rod so that the distance between the ends of the ring segments is adjustable for the purpose of placing the ring in compression relative to the manhole opening to thereby secure the adapter ring at the opening.

Preferably, the first and second valve members each include a stationary valve body having a seat portion, a movable valve element and stem, and a biasing device between the valve stem and the valve body urging the valve element against the seat portion of the valve body. The valve element remains seated until the force acting upon it in the direction opposite the force generated by the biasing device is greater than the force of the biasing device. When this condition occurs the movable valve element moves away from the seat'portion of the valve body to open the valve member. Each valve body comprises two pieces with a first piece on one side of the cover plate having a portion that extends through an opening in the plate and a second piece on the other side of the plate having a portion that snugly surrounds the portion of the first valve body piece that extends through the opening in the plate. A threaded connection may be provided between the portion of the first valve body piece that extends through the opening in the plate and the portion of the second valve body piece that snugly surrounds the first piece.

The valve bodies of the first and second valve members each includes a passageway that provides communication between the up side and down side of the cover plate when the valve member is open. Each passageway includes tapered portions.

BRIEF DESCRIPTION OF THE DRAWING Novel features and advantages of the present invention in addition to those mentioned above will become apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawing wherein:

FIG. 1 is a top plan view ofa manhole closure assembly according to the present invention;

FIG. 2 is a sectional view taken along line 2--2 of FIG. 1;

FIG. 3 is a side elevational view of a valve member according to the present invention;

FIG. 4 is a top plan view of the valve member shown in FIG. 3;

FIG. 5 is a bottom plan view of the valve member shown in FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is a partial side elevational view of another valve member according to the present invention, with portions broken away to show internal detail;

FIG. 8 is a partial side elevational view of an adapter ring according to the present invention; and

FIG. 9 is a partial side elevational view of another adapter ring according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring in more particularity to the drawing, FIGS. 1 and 2 illustrate a manhole closure assembly 10 for primarily preventing drainage and storm water from emptying into a manhole 12 that leads to a sewerage system. As iswell known, the upper end of most manhole constructions is surrounded by an annular manhole frame 14 embedded in a road bed 16 or similar surface construction. The annular manhole frame has an upper undercut 18 for supporting a standard manhole cover or lid (not shown). The manhole lid has passageways therein, as is well known.

The manhole cover assembly 10 of the present invention comprises a cover plate 20 fabricated from rigid metal or similar material including a pair of semicircular segments 22, 24 and a connector strip 26 that seals, supports and connects the semicircular segments along their diametral edges 28. The connector strip 26 may also be constructed of rigid metal and has an S-shaped cross section the openings of which are constructed and arranged to snugly receive the diametral portions 28 of the semicircular segments 22, 24 of the cover plate 20.

As explained more fully below, the cover plate 20 of the manhole closure assembly 10 is supported in covering relationship over the manhole 12 by an adapter ring 30. The ring 30 supports the arcuate edges 32 of the semicircular segments 22, 24 of the plate 20 as well as the ends 34 of the connector strip 26. The two-piece construction of the cover plate 20 enables the plate to be easily positioned in sealing relationship over the manhole opening. Caulking or other suitable material 36 is located between the adapter ring 30 and the arcuate edges 32 of the cover plate 20. Sealing material may also be located at the juncture between the diametral edges 28 and the connector strip 26 to provide an airtight seal of the cover plate over the manhole opening. The weight of the manhole cover assembly 10 is usually sufficient to hold it in place over the manhole opening. However, suitable anchoring structure may be provided if a more positive hold down is desired.

A first or pressure relief valve member 38 is secured to the semicircular segment 22 of the cover plate 20 for relieving internal pressure inside the manhole 12. Additionally, a second or vacuum relief valve 40 is secured to the semicircular segment 24 of the cover plate 20 for relieving vacuum that develops inside the manhole 12. As explained more fully below in conjunction with the details of FIGS. 4-6, the valve members 38, 40 function to relieve pressure and vacuum inside the manhole 12 when the pressure therein exceeds a predetermined amount such as, for example, five pounds per square inch above atmospheric pressure, and also to relieve vacuum in the manhole when it exceeds a predetermined amount, for example, five pounds per square inch below atmospheric pressure.

Referring now to FIGS. 3-6, the details of the valve member 38 are shown it being understood that the vacuum relief valve member 40 is identical to the valve 38 except that the vacuum valve 40 opens in a downward direction to relieve vacuum while the pressure valve 38 moves in an upward direction to relieve pressure. The pressure valve 38 includes a stationary valve body 42 composed of first and second pieces 44 and 46 with a valve seat portion 48 on the valve body piece 46. The valve 38 also includes a movable valve element 50 and valve stem 52, and a coil spring 54 that reacts between the valve stem and the valve body piece 44 via a disc or washer 56 associated with the body piece 44. A passageway 58 is located in the valve body 42 for providing communication between the up side and down side of the cover plate 20 when the valve is open. Portions of the passageway 58 are tapered at 60 for the purpose of providing a self-cleaning function, as explained more fully below.

The valve body 42 and movable valve element 50 of the valve 38 may be fabricated from thermoplastic material such as polyvinyl chloride and these components may be molded by techniques known in the art. As explained above, the valve body 42 is stationary with regard to the cover plate 20. In this regard, the first valve body piece 44 includes a portion 62 that extends through an opening 64 in the plate 20, and the second piece 46 has a portion 66 that snugly surrounds the portion 62 of the first valve body piece 44. The valve body pieces 44, 46 may be joined together in force fitting relationship or a bead of adhesive 68 may be provided to anchor the pieces together, as shown best in FIG. 6.

Coil spring 54 is designed to hold the movable valve element 50 against the stationary valve body 42 until the force acting upon the underside of the movable valve element is greater than the force of the coil spring 54 which acts in an opposite direction. Thus, when the pressure inside the manhole 12 exceeds 5 pounds per square inch, for example, the force generated by that pressure on the movable valve element 50 is sufficient to urge the valve element in an upward direction to thereby relieve the pressure inside the manhole. When the valve element opens, water, silt and other foreign material which accumulates on top of the cover is flushed out of the passageway 58 before the valve 38 closes. The tapered configuration of the passageway 58 functions to assist in maintaining it free of obstructions.

The vacuum reliefvalve 40 operates in a similar fashion to relieve vacuum build-ups inside of the manhole.

In this regard, when the downward pull on the exterior v of the movable valve element 50 exceeds the force generated by the coil spring 54 the valve is pulled open to thereby relieve the vacuum generated inside the manhole 12. On the other hand, when the force of the coil spring exceeds the downward pull on the movable valve element 50 the vacuum relief valve 40 is snapped closed. The vacuum relief valve 40 has the same selfcleaning characteristics as the pressure relief valve 38.

FIG. 7 illustrates another relief valve 70 fabricated of metal, such as aluminum, and including a threaded connection 72 between the first valve body piece 74 and the second valve body piece 76 of the stationary valve body 78. The threaded connection 72 comprises external threads on the first valve body piece 74 that cooperate with internal threads on the second valve body piece 76,, as shown in FIG. 7. The threaded connection 72 enables the valve body 78 to be anchored to the cover plate so that it is stationary relative to the plate. Otherwise, the relief valve member 70 is substantially similar to the relief valvemembers 38, 40 and operates in a similar fashion. The valve 70 may be used for relieving pressure and vacuum inside the manhole 12.

FIG. 8 illustrates details of the adapter ring upon which the manhole closure assembly 10 is supported. The adapter ring comprises a pair of arcuate segments 80, 82 and fastening structure 84 at the ends of the segments for joining them together to form the ring. In the embodiment shown in FIG. 8, the fastening structure includes an externally threaded rod 86 with internally threaded nuts 88 associated with the ends of the ring segments 80, 82. The nuts 88 on the rod are on opposite sides of a bracket 90 secured near the free end of each of the ring segments. The threaded rods extend through openings in the brackets, as shown in FIG. 8. In operation, the inner pair of nuts 88 at the ends where the ring segments 80, 82 are joined together are rotated to adjust the distance between the ends of the ring segments. When the circumference of the adapter ring 30 is just slightly less than the inside circumference of the manhole 14 the adapter is slipped into place and the same nuts are turned to further expand the adapter ring and place it in compression. The rod 86 is then locked in place by turning now the outer nuts at the ends where the ring segments are adjacent one another. The adapter ring is particularly useful when the annular manhole frame 30 does not include a frame upon which the closure assembly 10 can be rested.

FIG. 9 illustrates an alternate embodiment 92 of the adapter ring. In this embodiment the brackets 90 include internally threaded openings, and the externally threaded rod 86 includes a hexagonal nut 94 welded or otherwise secured to the mid portion of the rod. The threads on one-half of the rod 86 are left threads while the threads on the other rod half are right threads. Accordingly, when the hexagonal nut 94 is rotated in one direction the ring segments 80, 82 move away from one another and when the nut 94 is rotated in the other direction the ring segments'move toward one another. Ultimately, the adapter ring 92 is placed in compression inside the manhole frame 14 by first locating the adapter ring inside the manhole and then rotating the nut 94 until the ring is in compression inside the manhole.

Each of the embodiments of the present invention provides a manhole closure assembly for sealing off the opening of a manhole construction that leads to a sewerage system. The closure prevents storm and drainage water from emptying into the manhole. Excessive pressure inside the manhole is readily relieved when it exceeds a predetermined amount, and vacuum build-ups inside the manhole are relieved by a suitable vacuum reliefv What is claimed is:

l. The combination of a manhole closure assembly for preventing drainage and storm water from entering into a manhole opening, an annular manhole frame surrounding the upper portion of the manhole including means for supporting a lid in covering relationship over the manhole, and a separate support ring for the closure assembly adjacent the inside of the annular manhole frame including a closure supporting flange and means for placing the ring in compression against the inside of the annular manhole frame to thereby secure the ring to the frame, the closure assembly including a substantially circular cover plate the arcuate edge portions of which engage the closure supporting flange of the support ring, a first valve member secured to the cover plate constructed and arranged to relieve pressure inside the manhole when the pressure therein exceeds a predetermined amount, and a second valve member secured to the cover plate arranged to relieve vacuum inside the manhole when the vacuum therein exceeds a predetermined amount, and wherein the cover plate comprises a pair of semicircular segments, and a connector strip that seals and connects the semi- .circular segments together along their diametral edges.

2. The combination of a manhole closure assembly for preventing drainage and storm water from entering into a manhole opening, an annular manhole frame surrounding the upper portion of the manhole including means for supporting a lid in covering relationship over the manhole, and a separate support ring for the closure assembly adjacent the inside of the annular manhole frame including a closure supporting flange and means for placing the ring in compression against the inside of the annular manhole frame to thereby secure the ring to the frame, the closure assembly including a substantially circular cover plate the arcuate'edge portions of which engage the closure supporting flange of the support ring, a first valve member secured to the cover plate constructed and arranged to relieve pressure inside the manhole when the pressure therein exceeds a predetermined amount, and a second valve member secured to the cover plate arranged to relieve vacuum inside the manhole when the vacuum therein exceeds a predetermined amount, and wherein the cover plate comprises a pair of semicircular segments and a connector strip that seals and connects the semicircular segments together along their diametral edges, the connector strip having an S-shaped cross section the openings of which are constructed and arranged to snugly receive the diametral edge portions of the semicircular segments of the cover plate.

3. The combination of claim 2 in which the first valve member is secured to one of the semicircular segments of the cover plate and the second valve member is secured to the other semicircular segment of the cover plate. 

1. The combination of a manhole closure assembly for preventing drainage and storm water from entering into a manhole opening, an annular manhole frame surrounding the upper portion of the manhole including means for supporting a lid in covering relationship over the manhole, and a separate support ring for the closure assembly adjacent the inside of the annular manhole frame including a closure supporting flange and means for placing the ring in compression against the inside of the annular manhole frame to thereby secure the ring to the frame, the closure assembly including a substantially circular cover plate the arcuate edge portions of which engage the closure supporting flange of the support ring, a first valve member secured to the cover plate constructed and arranged to relieve pressure inside the manhole when the pressure therein exceeds a predetermined amount, and a second valve member secured to the cover plate arranged to relieve vacuum inside the manhole when the vacuum therein exceeds a predetermined amount, and wherein the cover plate comprises a pair of semicircular segments, and a connector strip that seals and connects the semicircular segments together along their diametral edges.
 2. The combination of a manhole closure assembly for preventing drainage and storm water from entering into a manhole opening, an annular manhole frame surrounding the upper portion of the manhole including means for supporting a lid in covering relationship over the manhole, and a separate support ring for the closure assembly adjacent the inside of the annular manhole frame including a closure supporting flange and means for placing the ring in compression against the inside of the annular manhole frame to thereby secure the ring to the frame, the closure assembly including a substantially circular cover plate the arcuate edge portions of which engage the closure supporting flange of the support ring, a first valve member secured to the cover plate constructed and arranged to relieve pressure inside the manhole when the pressure therein exceeds a predetermined amount, and a second valve member secured to the cover plate arranged to relieve vacuum inside the manhole when the vacuum therein exceeds a predetermined amount, and wherein the cover plate comprises a pair of semicircular segments and a connector strip that seals and connects the semicircular segments together along their diametral edges, the connector strip having an S-shaped cross section the openings of which are constructed and arranged to snugly receive the diametral edge portions of the semicircular segments of the cover plate.
 3. The combination of claim 2 in which the first valve member is secured to one of the semicircular segments of the cover plate and the second valve member is secured to the other semicircular segment of the cover plate. 